Question

如何检测旋转的CCSprite上的触摸？

我熟悉使用ccTouchesBegan和contentSize，anchorPoint等的一般技术，如果触摸在其范围内，可以检测精灵......但是我不知道一旦精灵旋转后如何继续角。

我希望sprite本身能够检测到触摸（封装）并通过委托将事件报告给另一个对象。

如果有人要分享一些代码......会很棒。

Answer 1

尝试使用CCNode convertTouchToNodeSpaceAR：方法将点转换为旋转坐标，然后您可以比较精灵边界。

我在CCNode上将其设为一个类别，因此可供任何CCNode或子类使用。

@interface CCNode (gndUtils)

// Lets a node test to see if a touch is in it.
// Takes into account the scaling/rotation/transforms of all 
// the parents in the parent chain.
// Note that rotation of a rectangle doesn't produce a rectangle 
// (and we are using a simple rectangle test)
//   so this is testing the smallest rectangle that encloses the rotated node.
// This does the converstion to view and then world coordinates
// so if you are testing lots of nodes, do that converstion manually
//
//  CGPoint touchLoc = [touch locationInView: [touch view]];  // convert to "View"
//  touchLoc = [[CCDirector sharedDirector] convertToGL: touchLoc]; // move to "World"
// and then use worldPointInNode: method instead for efficiency.

- (BOOL) touchInNode: (UITouch *) touch;

// allows a node to test if a world point is in it.
- (BOOL) worldPointInNode: (CGPoint) worldPoint;

@end

和实施：

@implementation CCNode (gndUtils)

- (BOOL) touchInNode: (UITouch *) touch
{
    CGPoint touchLoc = [touch locationInView: [touch view]];            // convert to "View coordinates" from "window" presumably
    touchLoc = [[CCDirector sharedDirector] convertToGL: touchLoc];     // move to "cocos2d World coordinates"

    return [self worldPointInNode: touchLoc];
}

- (BOOL) worldPointInNode: (CGPoint) worldPoint
{
    // scale the bounding rect of the node to world coordinates so we can see if the worldPoint is in the node.
    CGRect bbox = CGRectMake( 0.0f, 0.0f, self.contentSize.width, self.contentSize.height );    // get bounding box in local 
    bbox = CGRectApplyAffineTransform(bbox, [self nodeToWorldTransform] );      // convert box to world coordinates, scaling etc.
    return CGRectContainsPoint( bbox, worldPoint );
}
@end

Answer 2

@Dad的代码将节点的bbox转换为世界。对于旋转节点，这会扩展bbox，并且对于实际节点之外但在世界bbox内部的触摸，可以返回true。要避免这种情况，请将世界点转换为节点的坐标空间，并在那里测试本地点。

Answer 3

正如 Absinthe 所说 - poundev23 的代码实际上只检查旋转的精灵周围的BB。我写了正确的代码（但在Cocos2dx - c ++上） - 希望它对某人有所帮助：

CCSize size = this->getContentSize();
CCRect rect = CCRect(0, 0, size.width, size.height);
CCPoint pt = touch->locationInView();
pt = CCDirector::sharedDirector()->convertToGL(pt);
pt = CCPointApplyAffineTransform(pt, this->worldToNodeTransform());
bool b = CCRect::CCRectContainsPoint(rect, pt);

有一个很好的代码！

编辑：好的解决方案我把它转换成了目标C.

- (BOOL) containsTouchLocation:(UITouch *) touch
{
    CGSize size = self.contentSize;
    CGRect rect = CGRectMake(0, 0, size.width, size.height);
    CGPoint touchLocation = [touch locationInView: [touch view]];
    touchLocation = [[CCDirector sharedDirector] convertToGL:touchLocation];
    touchLocation = CGPointApplyAffineTransform(touchLocation, self.worldToNodeTransform);
    bool containsPoint = CGRectContainsPoint(rect, touchLocation);

    return containsPoint;
}

Cocos2d：检测旋转精灵的触摸？

3 个答案: